She says users enter personal details about menstrual cycles,
body temperatures, and other habits. The app adapts as the user
enters more and more data.

When the moment is right for conception, the app gives the user
and her partner an alert.

Levchin revealed the app at the D11 conference, a
technology-focused event. He was on stage talking
about cervical mucus, which was a change of pace from the
previous speakers like Facebook COO Sheryl Sandberg, Apple CEO
Tim Cook, and Twitter CEO Dick Costolo.

Levchin says the temperature of the cervical mucus is another
data point entered into the app because it helps figure out the
right time to get pregnant.